From: "NeilBrown" <neilb@suse.de>
To: Christoph Hellwig <hch@infradead.org>
Cc: mark delfman <markdelfman@googlemail.com>,
Linux RAID Mailing List <linux-raid@vger.kernel.org>
Subject: Re: xfs > md 50% write performance drop on .30+ kernel?
Date: Tue, 13 Oct 2009 12:57:16 +1100 [thread overview]
Message-ID: <bf6312ba46da06f3801de738337990b2.squirrel@neil.brown.name> (raw)
In-Reply-To: <20091013013352.GA24869@infradead.org>
On Tue, October 13, 2009 12:33 pm, Christoph Hellwig wrote:
> On Mon, Oct 12, 2009 at 05:58:20PM +0100, mark delfman wrote:
>> Hi... in recent tests we are seeing a 50% drop in performance from
>> XFS>MD on a 2.6.30 kernel (compared to a 2.6.28 kernel)
>>
>> In short: Performance to MD0 direct = circa 1.7GBsec (see below), via
>> xfs circa 850MBsec. On previous system (2.6.28) there was no drop in
>> performance (in fact often an increase).
>>
>> I am hopefully that this is simply a matter of barriers etc on the
>> newer kernel and MD, but we have tried many options and nothing seems
>> to change this so would very much appreciate advice.
>
> Did barrier support for RAID0 got introduced in 2.6.30?
No, though it is due to go in for 2.6.33
NeilBrown
next prev parent reply other threads:[~2009-10-13 1:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-12 16:58 xfs > md 50% write performance drop on .30+ kernel? mark delfman
2009-10-12 18:40 ` Richard Scobie
2009-10-13 1:33 ` Christoph Hellwig
2009-10-13 1:57 ` NeilBrown [this message]
2009-10-13 11:06 ` mark delfman
2009-10-13 11:09 ` Majed B.
[not found] ` <66781b10910130412x309d9de2l574ba12a9ed4100a@mail.gmail.com>
2009-10-13 11:15 ` Majed B.
2009-10-13 11:29 ` mark delfman
2009-10-13 14:30 ` Asdo
2009-10-13 15:13 ` mark delfman
2009-10-13 15:15 ` mark delfman
2009-10-13 22:52 ` Christoph Hellwig
2009-10-14 19:34 ` mark delfman
2009-10-27 10:28 ` Thomas Fjellstrom
2009-10-27 11:11 ` Thomas Fjellstrom
2010-01-02 6:54 ` fibre raid
2009-10-13 3:38 ` Richard Scobie
2009-10-13 10:21 ` Asdo
2009-10-13 10:34 ` Mikael Abrahamsson
2009-10-13 14:49 ` Asdo
2009-10-13 19:53 ` Richard Scobie
2009-10-13 21:52 ` mark delfman
2009-10-13 18:49 ` Greg Freemyer
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